Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ALDOLASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources

Physico-chemical evidence for the interaction between aldolase and glyceraldehyde-3-phosphate dehydrogenase.

Polarization of fluorescence measurements of aldolase and D-glyceraldehyde-3-phosphate dehydrogenase labeled with fluorescein isothiocyanate have been used to detect the possible formation of a soluble complex between the proteins. The results suggest an interaction between aldolase and D-glyceraldehyde-3-phosphate dehydrogenase with an apparent dissociation constant 3 X 10(-7) M and an apparent stoichiometry of two aldolase tetramers bound per tetramer of D-glyceraldehyde-3-phosphate dehydrogenase.

Fluoresceins↗

Fructose-1,6-bisphosphate aldolase from rabbit liver. Reaction mechanism and physiological function.

Liver and muscle aldolase display similar reaction mechanisms. Both the enzymes, by reacting with dihydroxyacetone phosphate, form an acid-labile intermediate which is in rapid equilibrium with an eneamine intermediate. Differences are found in the equilibrium concentration of the acid-labile intermediate, which represents approximately 25% of the total intermediates in the liver (this paper) and 60% in the muscle enzyme [E. Grazi and G. Trombetta, Biochem. J. 175, 361 (1978)] and in the rate of formation of the eneamine intermediate which is much slower in the liver enzyme. Furthermore, with liver aldolase, the rate by which the C-3H bond of dihydroxyacetone phosphate is cleaved is increased by 60 times in the presence of glyceraldehyde 3-phosphate. This, mechanistically, indicates that glyceraldehyde 3-phosphate is bound to the enzyme before the formation of the eneamine from dihydroxyacetone phosphate, and, physiologically, that in liever aldolase the gluconeogenetic activity is favoured over the glycolytic activity.

Animals↗

Identification of the C-1-phosphate-binding arginine residue of rabbit-muscle aldolase. Isolation of 1,2-cyclohexanedione-labeled peptide by chemisorption chromatography.

The arginine-specific reagent 1,2-cyclohexanedione reacts selectively with the arginine residue of the C-1-phosphate-binding site of aldolase and inactivates the enzyme. The labeled peptide isolated from tryptic digests of inactivated aldolase was found to correspond to the sequence Leu-43 to Arg-56, the residue modified by cyclohexanedione being Arg-55. This peptide was absent form digests of aldolase treated in the same way but protected from inactivation by the presence of substrate, thus correlating modification of Arg-55 with loss of activity. Selective isolation ofthe peptide containing the modified arginine residue was effected by chemisorption chromatography on boric acid gel, a procedure exploiting the specific interaction of matrix-bound boric acid groups with vicinal cis-hxdroxyl groups of cyclohexanedione-modified arginine side chains.

Animals↗

Amino acid sequence around the active site of two class I fructose-1,6-bisphosphate aldolases from staphylococci.

The amino acid sequences of a 26-residue segment containing the active-site lysyl residue of the class I fructose-1,6-bisphosphate aldolases from Staphylococcus aureus and Staphylococcus epidermidis have been determined. The sequence homology within the active sites between these enzymes and those from several eucaryotic class I aldolases showed a maximum of 21%. The similarity may indicate the origin of both procaryotic and eucaryotic class I aldolases from a common ancestor.

Amino Acid Sequence↗

Simultaneous purification of hexokinase, class-I fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase from Trypanosoma brucei.

A method is presented for the simultaneous purification of hexokinase, fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase, and the partial purification of glycerol-3-phosphate dehydrogenase (NAD+), 6-phosphofructokinase, glucosephosphate isomerase, and glycerol kinase from Trypanosoma brucei. As a first step, the glycosomes, microbody-like organelles of Trypanosomatidae, containing almost exclusively enzymes involved in glucose and glycerol metabolism [Opperdoes, F. R. and Borst, P. (1977) FEBS Lett. 80, 360-364], were purified eightfold from homogenates with an average yield of 38%. Subsequently, the glycosomal content was subjected to hydrophobic interaction chromatography on phenyl-Sepharose. This step results in pure hexokinase (15% final yield) and almost pure triosephosphate isomerase, while the other glycosomal enzymes elute as mixtures of two or three enzymes. Triosephosphate isomerase was further purified to homogeneity on CM-cellulose (33% final yield), while phosphoglycerate kinase and fructose-bisphosphate aldolase were separated from each other and purified to homogeneity by affinity chromatography using ATP-Sepharose (25% and 30% final yields, respectively). Fructose-bisphosphate aldolase was further characterized as a typical class I enzyme.

Animals↗

Human aldolase A gene. Structural organization and tissue-specific expression by multiple promoters and alternate mRNA processing.

The complete nucleotide sequence of the human aldolase A isoenzyme gene is reported. The cloned gene sequence, spanning 7530 bp, includes twelve exons and occurs as a single copy per haploid human genome. The structural organization of the gene is quite complex: eight exons containing the coding sequence are common to all mRNAs extracted from human and other mammalian sources; four additional exons are present in the 5' untranslated region, of these one is contained in the ubiquitous type of mRNA, the second is in the muscle-specific type of mRNA and the third and fourth are in a minor species of mRNA found in human liver tissue. Furthermore, the determined sequence includes 1000 nucleotides upstream from the first exon (exon I) in the 5' flanking region, and 400 nucleotides, which include the polyadenylation signal, downstream from the termination codon. S1-nuclease-protection analysis of the 5' end of mRNA extracted from human cultured fibroblasts, muscle and hepatoma cell lines indicates the existence of four different transcription-initiation sites. The latter are also supported by the presence of conventional sequences for eukaryotic promoters. Therefore, the four promoters on the same gene generate different tissue-specific transcripts, which share the translated sequence, but each has a unique 5' untranslated region as a result of differential mRNA processing. The nucleotide homology at the coding region and the intron-exon organization of the three human and mammalian aldolase A, B and C genes confirm that they arose from a common ancestral gene, and that aldolase B diverged first.

Base Sequence↗

Thermostable aldolase from Thermus aquaticus.

Data are presented on the purification and properties of the thermostable fructose-1,6-diphosphate aldolase of Thermus aquaticus, a nonsporulating, extreme thermophile. The enzyme shows little activity at temperatures below 60 C and optimal activity at about 95 C. The enzyme was purified 43-fold by diethylaminoethyl cellulose column chromatography and Sephadex G-200 gel filtration. The enzyme is activated by high concentrations of NH(4) (+) and low concentrations of Fe(2+) and Co(2+) and is strongly inhibited by ethylenediaminetetraacetic acid (EDTA). The activation by Fe(2+) and Co(2+) and the inhibition by EDTA are both reversed by dialysis. The enzyme is greatly activated by cysteine and less so by other sulfhydryl compounds. Activation by cysteine is reversible by dialysis. The purified enzyme had a molecular weight as determined by Sephadex G-200 gel filtration of 140,000; after incubation of enzyme with cysteine, another molecular species was also found with a molecular weight of 70,000. The purified enzyme is stable at low protein concentrations to 97 C but is rapidly inactivated at 105 C. In cysteine the enzyme is more heat labile; heat inactivation in the presence of cysteine is prevented by substrate, although, in the absence of cysteine, substrate partially labilizes the enzyme to heat. The temperature optimum for enzyme activity is several degrees lower in the presence of cysteine than in its absence, and the K(m) is threefold lower. It is concluded that the T. aquaticus enzyme resembles some other aldolases of Rutter's class II, except for its extreme heat stability. The T. aquaticus enzyme is compared with that of Bacillus stearothermophilus, a moderate thermophile. Although the T. aquaticus enzyme is considerably more heat stable, the enzymes from the two thermophiles have many similarities. New data are presented which show that the B. stearothermophilus aldolase is metal ion-dependent, in disagreement with earlier reports.

Bacillus↗

Rapid cessation of phospholipid synthesis in fructose-1,6-diphosphate aldolase mutants of Escherichia coli.

Escherichia coli GH352, which was originally described as a temperature-sensitive strain containing a thermolabile acyl coenzyme A:monoacylglycerol 3-phosphate acyltransferase, does not now contain a thermolabile form of this enzyme. It has a defect in fructose-1,6-diphosphate aldolase and at least one additional temperature-sensitive lesion. Both strains GH352 and NP315, a temperature-sensitive aldolase mutant, show rapid cessation of 32-P1 incorporation into nucleic acids and phospholipids at 42 C. These characteristics of strain GH352 are therefore no longer attributed to thermolabile phospholipid synthesis, but can be attributed to the fructose-1,6-diphophate aldolase lesion.

Acyltransferases↗

Fast-muscle-specific expression of human aldolase A transgenes.

The expression of the human aldolase A gene is controlled by three alternative promoters. In transgenic mice, pN and pH are active in all tissues whereas pM is activated specifically in adult muscles composed mainly of fast, glycolytic fibers. To detect potential regulatory regions involved in the fast-muscle-specific activation of pM, we analyzed DNase I hypersensitivity in a 4.3-kbp fragment from the 5' end of the human aldolase A gene. Five hypersensitive sites were located near the transcription initiation site of each promoter in those transgenic-mouse tissues in which the corresponding promoter was active. Only one muscle-specific hypersensitive site was detected, mapping near pM. To functionally delimit the elements required for muscle-specific activity of pM, we performed a deletion analysis of the aldolase A 5' region in transgenic mice. Our results show that a 280-bp fragment containing 235 bp of pM proximal upstream sequences together with the noncoding M exon is sufficient for tissue-specific expression of pM. When a putative MEF-2-binding site residing in this proximal pM region is mutated, pM is still active and no change in its tissue specificity is detected. Furthermore, we observed a modulation of pM activity by elements lying further upstream and downstream from pM. Interestingly, pM was expressed in a tissue-specific way in all transgenic mice in which the 280-bp region was present (32 lines and six founder animals). This observation led us to suggest that the proximal pM region contains elements that are able to override to some extent the effects of the surrounding chromatin.

Animals↗

Aldolase B mutations in Italian families affected by hereditary fructose intolerance.

Hereditary fructose intolerance (HFI) is an inborn error of metabolism caused by aldolase B deficiency. The aldolase B gene has been cloned and the following mutations causing HFI have been identified: A149P (a G----C transversion in exon 5), A174D (a C----A transversion in exon 5), L288 delta C (a base pair deletion in exon 8), and N334K (a G----C transversion in exon 9). We have investigated the occurrence of these mutations in 11 Italian patients affected by HFI using PCR and hybridisation to specific oligomers. We found that four patients were homozygous for the A149P mutation, two patients were homozygous for the A174D mutation, three patients were compound heterozygotes for both the A149P and A174D mutations, one patient was homozygous for the N334K mutation, and one patient did not show any of the reported mutations (HFI diagnosis carried out by aldolase B assay). The L288 delta C mutation has not been found in this survey.

Base Sequence↗

Null alleles of the aldolase B gene in patients with hereditary fructose intolerance.

We report three new mutations in the gene for aldolase B that are associated with hereditary fructose intolerance (HFI). Two nonsense mutations create opal termination codons: R3op (C-->T, Arg3-->ter, exon 2) was found in homozygous form in four affected members of a large consanguineous Turkish pedigree and R59op (C-->T, Arg59-->ter, exon 3) was found on one allele in a woman of Austrian origin known to harbour one copy of the east European mutation, N334K (Asn334-->Lys). The third mutation occurred in a French HFI patient known to be heterozygous for the widespread mutation, A174D (Ala174-->Asp): a single mutation, G-->A, in the consensus acceptor site 3' of intron 6 was found on the remaining allele. These mutations are predicted to abrogate synthesis of functional protein and thus represent null alleles of aldolase B. The mutant alleles can be readily detected in the amplification refractory mutation system (ARMS) or (for R59op and 3' intron 6) by digestion of amplified genomic fragments with DdeI or A1wNI, respectively, to facilitate direct diagnosis of HFI by molecular analysis of aldolase B genes.

Alleles↗

Neonatal screening for hereditary fructose intolerance: frequency of the most common mutant aldolase B allele (A149P) in the British population.

Hereditary fructose intolerance (HFI) causes severe and sometimes fatal metabolic disturbances in infants and children but responds to dietary treatment. To determine the practicability of screening newborn infants for HFI, we have investigated the frequency of the most common and widespread mutant allele of aldolase B, A149P, in the neonatal population. The polymerase chain reaction was used to amplify aldolase B exon 5 genomic sequences in DNA present in dried blood specimens preserved on Guthrie cards. The A149P mutation was identified by discriminatory hybridisation to allele specific oligonucleotides and confirmed independently by digestion with the restriction endonuclease BsaHI. Twenty-seven A149P heterozygotes were identified by the molecular analysis of aldolase B genes in blood samples obtained from a random cohort of 2050 subjects born in 1994 and 1995, 1.32 +/- 0.49% (95% confidence level). Although no A149P homozygotes were identified, the data allow the frequency of 1 in 23,000 homozygotes for this allele to be predicted. Our findings have implications for establishing an interventional mass screening programme to identify newborn infants with HFI in the UK.

Alleles↗

Aldolase isoenzymes in liver cirrhosis and primary liver cell cancer.

The isoenzymatic pattern of aldolase was determined by immunoprecipitation with specific anti-aldolase A, B and C sera in 21 pathological liver tissues and in the sera of normals (n equals 20), liver cirrhotics (n equals 52) and hepatoma patients (n equals 22). The increase of aldolase A in primary liver cell carcinoma is not reflected in the sera of these patients, cannot be used for diagnostic purposes and is not hepatoma-specific.

Animals↗

Aldolase activity and cross-reacting material in lymphocytes of aged individuals.

Aldolase activity was determined in human lymphocytes from 21 donors aged 18-84 years. The lymphocyte extracts contained exclusively aldolase A isozyme. No significnat difference in enzyme activity between adult (18-41 years) and old (56-84 years) age groups was observed. There was also no significant decrease with age of 'cross-reacting material' as determined with monospecific anti-aldolase A antibodies.

Adolescent↗

Hemolytic anemia and severe rhabdomyolysis caused by compound heterozygous mutations of the gene for erythrocyte/muscle isozyme of aldolase, ALDOA(Arg303X/Cys338Tyr).

Aldolase (E.C. 4.1.2.13), a homotetrameric protein encoded by the ALDOA gene, converts fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate. Three isozymes are encoded by distinct genes. The sole aldolase present in red blood cells and skeletal muscle is the A isozyme. We report here the case of a girl of Sicilian descent with aldolase A deficiency. Clinical manifestations included transfusion-dependent anemia until splenectomy at age 3 and increasing muscle weakness, with death at age 4 associated with rhabdomyolysis and hyperkalemia. Sequence analysis of the ALDOA coding regions revealed 2 novel heterozygous ALDOA mutations in conserved regions of the protein. The paternal allele encoded a nonsense mutation, Arg303X, in the enzyme-active site. The maternal allele encoded a missense mutation, Cys338Tyr, predicted to cause enzyme instability. This is the most severely affected patient reported to date and only the second with both rhabdomyolysis and hemolysis.

Amino Acid Sequence↗

Aldolase C/zebrin gene regulation by prolactin during pregnancy and lactation.

Prolactin (PRL) is necessary for the genesis of mammary alveolar buds and for lactation. A cDNA library enriched for PRL-dependent genes was made by suppression subtractive hybridization. Aldolase C/zebrin (AldC/zebrin), a brain-specific aldolase, was found to be PRL-dependent in the mouse mammary glands. AldC/zebrin was preferentially expressed in the alveolar buds. Expression of the gene in the ovary was also evident. During pregnancy, mammary AldC/zebrin mRNA levels were elevated beginning at midpregnancy (d 10 of pregnancy) in accordance with the genesis of the lobuloalveolar system, and the expression level was gradually increased through the end of pregnancy. Lactating mammary gland contained a very high level of AldC/zebrin mRNA, and the gene expression decreased during involution. By contrast, levels of aldolase A and B mRNA expression in the mammary glands were less affected by pregnancy and lactation. The selective regulation of AldC/zebrin may contribute to a shift in nutrient metabolism during pregnancy and lactation to facilitate epithelial growth and biosynthesis of milk constituents.

Animals↗

Membrane-bound fructose 1,6-bisphosphate aldolase: catalytic activity and mechanisms of desorption.

Fructose 1,6-bisphosphate aldolase [EC 4.1.2.13] in rat liver was found to be bound to the intracellular membraneous structures such as microsomes and nuclear membranes when the animals were fasted for 48 hr or administered tryptophan. Upon refeeding the rats the aldolase was released into the cytosol. The membrane-bound aldolase was almost inactive, showing about 50-fold larger Km and a smaller Vmax (37%) as compared with those of the free enzyme. The enzyme was released cooperatively from the membrane by exposure to fructose 1,6-bisphosphate, glyceraldehyde 3-phosphate or dihydroxyacetone phosphate at low concentrations. Apparent desorption constants (Kd, concentrations necessary for 50% desorption of enzyme) for fructose 1,6-bisphosphate of the enzymes bound to microsomes, mitochondria and nuclei were estimated to be 8 X 10(-5), 6.1 X 10(-6), and 4.8 X 10(-6)M, respectively, at pH 7.3. With the microsome-bound enzyme Kd values of 3.9 X 10(-4), 4.1 X 10(-4), 2.7 X 10(-3), 1.1 X 10(-2) and 2.0 X 10(-2) M were obtained for glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, fructose 1-phosphate, fumarate, and KCl, respectively. Strong cooperativities were observed in the enzyme desorption by the substances which showed large Kd values.

Animals↗

[Molecular hybridization of native and modified subunits of lactate dehydrogenase isoenzymes and aldolase A in rats].

Experimental conditions for the molecular hybridization in vitro between iodine and native subunits of isoenzymes 1 and 5 of lactate dehydrogenase (LDH) are described. It is also shown that the covalently fixed on the polyacrylamide beads rat J125 labelled LDH-5 and J125 labelled aldolase A, under conditions of complete dissociation of the quaternary structure of these enzymes, only one of the four subunits remain bound with the beads. Subunit of LDH-5, which is covalently bound with the polyacrylamide beads, is capable to hybridize (reassociated) with 3 native subunits. In addition, the immobilized LDH-5 subunits and aldolase A are capable to hybridize with J125 labelled subunits of these enzymes. Thus, when thyrosine, lysine and N-terminal amino acids are modified, subunits of LDH-5 and aldolase A retain their capacity to restore their quaternary structures.

Amino Acids↗